Meta-RL Gradient Estimation with Control Variates

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Solution Overview

Problem

Deep reinforcement learning neural networks face high sample complexity and fail to adapt efficiently to new tasks, leading to poor sample efficiency and unstable training due to high variance in gradient estimation.

Innovation Solution

Incorporating control variates into gradient estimation via automatic differentiation and extending the meta-learning framework to learn control variates, enabling efficient learning across a distribution of Markov decision processes for related tasks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If deep reinforcement learning is used for task learning, then the model can handle complex tasks including game playing and natural language processing, but the sample complexity becomes excessively high and the model fails to adapt to new situations

Engineering Contradiction:
Improveadaptability to new tasksVSAvoidsample complexity
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent applies preliminary action by pre-training the neural network model on a distribution of related tasks before deployment. This meta-training phase prepares the model with generalized knowledge that enables rapid adaptation to new tasks within the same distribution, reducing the samples needed for each new task.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements universality by designing a single neural network model that can handle multiple related tasks within a task distribution. The model learns task-agnostic representations and adaptation mechanisms that allow it to function across different tasks (e.g., different games or NLP tasks) without task-specific retraining.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If standard gradient estimation is used in meta-reinforcement learning, then the training process can proceed, but the high variance in gradient estimation leads to unstable training and poor sample efficiency

Engineering Contradiction:
Improvetraining stabilityVSAvoidsample efficiency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent introduces control variates as intermediary components in the gradient estimation process. These control variates serve as mediators that reduce the variance of gradient estimates by subtracting out high-variance components, leading to more stable and sample-efficient training without introducing bias.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements feedback mechanisms where gradient estimates from previous iterations are used to adjust and improve subsequent gradient estimates. This feedback loop allows the system to learn from past gradient variations and progressively reduce variance, improving both training stability and sample efficiency.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS11922323B2Meta-reinforcement learning gradient estimation with variance reduction
Publication Date: 2024.03.05 SALESFORCE INC
  • US11922323B2 patent drawing
  • US11922323B2 patent drawing
  • US11922323B2 patent drawing

AI summary

A method for deep reinforcement learning using a neural network model includes receiving a distribution including a plurality of related tasks. Parameters for the reinforcement learning neural network model is trained based on gradient estimation associated with the parameters using samples associated with the plurality of related tasks. Control variates are incorporated into the gradient estimation by automatic differentiation.